Those provided by IANA in the TZDB are identified by a value such as America/New_York.

很多基于互联网的API使用的IANA时区，但对于众多的原因之一，可能需要将其转换为Windows时区ID，反之亦然。

Many Internet-based APIs use the IANA time zones, but for numerous reasons one might need to convert this to a Windows time zone id, or vice-versa.

如何在.net中可能？

How can this be accomplished in .Net?

推荐答案

有关Windows和IANA时区标识符之间的转换数据的主要来源是的单向code CLDR 。

The primary source of the data for conversion between Windows and IANA time zone identifiers is part of the Unicode CLDR.

在大多数情况下，一个IANA时区可以被映射到一个单一的视窗时区。但相反的是不正确的。一个单一的Windows时区可能映射到多个IANA时区。

In most cases, an IANA time zone can be mapped to a single Windows time zone. But the reverse is not true. A single Windows time zone might be mapped to more than one IANA time zone.

在除了作为一个卓越的日期和时间的API，在野田佳彦时间库包含了CLDR映射的嵌入式副本。

In addition to being a superior date time API, the Noda Time library contains an embedded copy of the CLDR mappings.

下面的功能可以被用来转换：

The following functions can be used to convert:

// This will return the Windows zone that matches the IANA zone, if one exists.
public string IanaToWindows(string ianaZoneId)
{
    var utcZones = new[] { "Etc/UTC", "Etc/UCT", "Etc/GMT" };
    if (utcZones.Contains(ianaZoneId, StringComparer.Ordinal))
        return "UTC";

    var tzdbSource = NodaTime.TimeZones.TzdbDateTimeZoneSource.Default;

    // resolve any link, since the CLDR doesn't necessarily use canonical IDs
    var links = tzdbSource.CanonicalIdMap
        .Where(x => x.Value.Equals(ianaZoneId, StringComparison.Ordinal))
        .Select(x => x.Key);

    // resolve canonical zones, and include original zone as well
    var possibleZones = tzdbSource.CanonicalIdMap.ContainsKey(ianaZoneId)
        ? links.Concat(new[] {tzdbSource.CanonicalIdMap[ianaZoneId], ianaZoneId})
        : links;

    // map the windows zone
    var mappings = tzdbSource.WindowsMapping.MapZones;
    var item = mappings.FirstOrDefault(x => x.TzdbIds.Any(possibleZones.Contains));
    if (item == null) return null;
    return item.WindowsId;
}

// This will return the "primary" IANA zone that matches the given windows zone.
// If the primary zone is a link, it then resolves it to the canonical ID.
public string WindowsToIana(string windowsZoneId)
{
    if (windowsZoneId.Equals("UTC", StringComparison.Ordinal))
        return "Etc/UTC";

    var tzdbSource = NodaTime.TimeZones.TzdbDateTimeZoneSource.Default;
    var tzi = TimeZoneInfo.FindSystemTimeZoneById(windowsZoneId);
    if (tzi == null) return null;
    var tzid = tzdbSource.MapTimeZoneId(tzi);
    if (tzid == null) return null;
    return tzdbSource.CanonicalIdMap[tzid];
}

请注意，该映射UTC已被另案处理。这是因为CLDR错误地映射UTC到ETC / GMT和ETC / GMT未设置起来作为TZDB链接ETC / UTC。 更多关于此这里。

Note that the mapping for UTC has to be handled separately. This is because the CLDR erroneously maps UTC to "Etc/GMT", and "Etc/GMT" is not set up as a link to "Etc/UTC" in the tzdb. More on this here.